How to Silence Unknown Callers on iPhone

If your iPhone rings four or five times a day with spam calls, fake IRS warnings, and robocalls about your car warranty, there is a powerful built-in setting that can stop almost all of it: Silence Unknown Callers. When this setting is turned on, your iPhone only rings when someone in your contact list, your recent outgoing calls, or Siri suggestions calls you. Every other caller, including all those random spam numbers, goes straight to voicemail without your phone ringing or vibrating once. The caller can still leave a voicemail if they want, but your day is no longer interrupted.

Apple added the Silence Unknown Callers setting in iOS 13 (released in 2019), and every iPhone running iOS 17 or later has it. To check your iOS version, open Settings, tap General, then tap About, and look at the iOS Version line. Almost every iPhone in use in 2026 runs iOS 17 or newer, so the setting is available. The feature is free, takes ten seconds to turn on, and does not require a phone app, a subscription, or help from your phone company. It is one of the most effective free tools against phone scams that has ever been built into a phone.

There is one trade-off to know about before you turn it on. If a real but unknown caller tries to reach you, like a new doctor's office, a delivery driver, a hospital calling about a family member, or someone returning your call from a number not in your contacts, your phone will not ring. The call will go to voicemail. For most people, that is a fair trade for ending spam, because you can listen to voicemails at your own pace and call back the real ones. To make sure you do not miss anything important, the setting saves all silenced calls in your Recents tab so you can scroll through and check.

A few things to do before turning the setting on. First, add anyone who calls you often to your contacts list, including your doctor, pharmacy, family members, neighbors, church, and any service you actually use. The setting only silences callers not in your contacts, so the more real people in your contacts, the fewer real calls go to voicemail. Second, check your voicemail at least once a day so you do not miss an important real call. Third, know that you can turn the setting off at any time if it feels too strict. And you can turn it back on later. There is no penalty for trying it.